1. Field of the Invention
The present invention relates to a door lock system for a vehicle.
2. Description of the Related Art
When a door-opening operation is performed on a door lock system in a locked position using an outside handle of a vehicle while an unlocking operation is simultaneously performed using an inside lock knob of the vehicle, the door-opening and the unlocking operations interfere each other. This may bring a state (hereinafter, “panic state”) in which neither the door-opening operation nor the unlocking operation is attained. For example, Japanese Patent Application Laid-open No. 2005-282221 discloses a conventional door lock system provided with anti-panic mechanism for avoiding such a panic state.
The conventional door lock system includes a ratchet lever, an opening lever, a sector gear, a link lever, an anti-panic lever, and a spring. The ratchet lever is interconnected with a ratchet and disengages the ratchet from a latch. The opening lever is rotatable in response to a door-opening operation performed on an outside handle. The sector gear, which is rotatably supported by a gear shaft, moves from a locked position to an unlocked position in response to an unlocking operation, and moves from the unlocked position to the locked position in response to a locking operation. The link lever, which is rotatably supported on an end of the opening lever, moves from a transmitting position, at which the ratchet lever is allowed to disengage the ratchet from the latch, and a non-transmitting position, at which the ratchet lever is not allowed to disengage the ratchet from the latch. One end of the anti-panic lever is rotatably supported by the gear shaft and the other end is coupled to the link lever. As the sector gear moves, the anti-panic lever causes the link lever to move to and from the transmitting position and the non-transmitting position. One end of the spring is engaged with the sector gear, and the other end of the spring is engaged with the anti-panic lever. Hence, the spring nests between the anti-panic lever and the sector gear and urges the anti-panic lever toward the sector gear.
In the conventional door lock system, when the outside handle is operated to open the door, the opening lever is moved from a non-operable position to an operable position, causing the link lever to move upward into contact with an abutting portion of the ratchet lever. This in turn moves the ratchet lever upward, and disengages the ratchet from the latch. Thus, the door can be opened with respect to a vehicle body.
When a locking operation is performed through a drive motor or the inside lock knob on the door in a closed position, the sector gear is moved from the unlocked position to the locked position, thereby pushing the anti-panic lever. Hence, the anti-panic lever is moved integrally with the sector gear, which in turn moves the link lever from a transmittable position to a non-transmittable position. Thus, the door lock system is locked.
When, in the locked state, the inside lock knob is operated in a direction to unlock the door, the sector gear is moved from the locked position to the unlocked position. This movement causes the anti-panic lever to be moved following the sector gear by a resilient force of the spring, and hence moves the link lever from the non-transmittable position to the transmittable position. Thus, the door lock system is unlocked.
When, in the locked state, the outside handle is operated to open the door while the inside lock knob is operated in the direction to unlock the door, the sector gear is moved from the locked position to the unlocked position, and the link lever comes into contact with a side face of the ratchet lever and stays at the non-transmittable position. When thereafter the outside handle is released to move the link lever downward, the resilient force of the spring moves the link lever to the transmittable position. Thus, the door lock system is unlocked. When the outside handle is operated to open the door again in this state, the door can be opened.
In the conventional door lock system having the anti-panic mechanism, the anti-panic lever is coupled between the sector gear and the link lever with the spring interposed between the sector gear and the anti-panic lever. Accordingly, the number of components is increased and the structure is complicated, which poses a problem of an increase in the man-hours required for assembly and in the manufacturing cost.